Comparison of retinal nerve fiber layer thickness between normal population and patients with diabetes mellitus using optical coherence tomography

Abstract

Objective: To compare the difference in peripapillary Retinal Nerve Fibre Layer (RNFL) thickness between normal population and Type-II diabetic patients without diabetic retinopathy using Spectral Domain Optical Coherence Tomography (SD OCT).

Methods: This cross sectional study was carried out at PNS Shifa Naval Hospital, from May 2017 to November 2017. Out of 200 eyes, 100 eyes were of normal individuals and 100 eyes were of Type-II diabetic patients without diabetic retinopathy. Both groups were age and gender matched. Average RNFL thickness, along with RNFL of each quadrant of individuals was noted using SD OCT, and compared between two groups.

Results: Mean age of study population was 44.63 ± 4.30 years. Mean axial length was 23.46 ± 0.59 mm. Mean peripapillary RNFL thickness was 126.98 ± 10.07 µm in Group-A (normal individuals), and 120.77 ± 5.41 µm in Group-B (Type-II diabetics). Difference in mean RNFL thickness, as well as RNFL thicknesses of each quadrant was statistically significant between both groups (p-value < 0.001).

Conclusion: Diabetic patients have thin RNFL as compared to normal individuals, and must be taken in account while making diagnosis of any disease based on thinning of RNFL.

Keywords: Diabetic neuropathy; Optical coherence tomography; Retinal nerve fibre layer thickness.